Ah, it is a Windows "feature" - the arrow key operation.
Testing it in various Control Panel panels, I see where both left/right arrows and up/down arrows control left/right movement of a slider and once the slider is selected you can not get out of that selection using the arrow keys. Had not noticed that in Windows before.
I guess it would be too much to ask for Jim to correct this oddity in the OS.
I know you think you understand what you thought I said,
but I'm not sure you realize that what you heard is not what I meant!